1. Field of the Invention
The present invention generally relates to a lane departure avoidance system. More specifically, the present invention relates to a lane departure avoidance system that detects rumble strips in the road to determine if a vehicle is departing from a lane.
2. Background Information
Many of the traffic fatalities that occur are caused by a vehicle departing from its driving lane. Such lane departures include both a vehicle driving off a road or shoulder of the road, and a vehicle crossing lanes into an oncoming lane on an undivided road. Often inattentive driving and/or driving while drowsy tend to lead to such lane departures. In an effort to combat this, transportation authorities have begun to place rumble strips into roads. Rumble strips are bumps or indentations in the surface of a road such that when a vehicle's tire drives over a rumble strip, noise and/or vibration is generated to make the driver aware that he or she is driving off the road. Rumble strips of varying locations and varying patterns and shapes are used based on where the rumble strip is located in respect to the road. For example, a different type of rumble strip may be utilized to separate oncoming lanes as compared to the type of rumble strips that are used to line the sides of roads.
Recently, several proposals have been made to equipped vehicles with lane departure avoidance systems that provide a warning to the driver and/or perform an automatic countermeasure when the host vehicle may depart from a driving lane. Often, these lane departure avoidance systems rely on lane markers rely in determining if the host vehicle may depart from a driving lane. However, sometimes the lane markers can be difficult to detect by the host vehicle. Thus, the lane departure avoidance system may not be able to accurately determine a lane departure rate.
In view of the above, it will be apparent to those skilled in the art from this disclosure that there exists a need for an improved lane departure avoidance system. This invention addresses this need in the art as well as other needs, which will become apparent to those skilled in the art from this disclosure.